我花了好几个小时试图找出这个问题，并按照类似问题的解决方案，但到目前为止没有任何工作。因为我已经没有使用的解决方案了，所以我开始感到沮丧。
我试图通过HttpWebRequest将文件上传到服务器。连接每次都在HttpWebRequest.GetRequestStream（）超时。在这里阅读问题，我已经看到这是连接没有妥善处理的问题。我认为我正确地关闭了连接，并且我的reposnse流也被封装在using块中，正如许多人在此建议的那样。
这是我的代码：
HttpWebRequest requestToServer = (HttpWebRequest)WebRequest.Create(url);
// Define a boundary string
string boundaryString = "----";
// Turn off the buffering of data to be written, to prevent
// OutOfMemoryException when sending data
requestToServer.AllowWriteStreamBuffering = false;
// Specify that request is a HTTP post
requestToServer.Method = WebRequestMethods.Http.Post;
// Specify that the content type is a multipart request
requestToServer.ContentType
= "multipart/form-data; boundary=" + boundaryString;
// Turn off keep alive
requestToServer.KeepAlive = false;
ASCIIEncoding ascii = new ASCIIEncoding();
string boundaryStringLine = "\r\n--" + boundaryString + "\r\n";
byte[] boundaryStringLineBytes = ascii.GetBytes(boundaryStringLine);
string lastBoundaryStringLine = "\r\n--" + boundaryString + "--\r\n";
byte[] lastBoundaryStringLineBytes = ascii.GetBytes(lastBoundaryStringLine);
string fileUrl = file;
// Get the byte array of the string part of the myFile content
// disposition
string myFileContentDisposition = string.Format(
"Content-Disposition: form-data;name=\"{0}\"; "
+ "filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n",
"myFile", Path.GetFileName(fileUrl), Path.GetExtension(fileUrl));
byte[] myFileContentDispositionBytes =
ascii.GetBytes(myFileContentDisposition);
var name = Path.GetFileName(fileUrl);
FileInfo fileInfo = new FileInfo(fileUrl);
// Calculate the total size of the HTTP request
long totalRequestBodySize = boundaryStringLineBytes.Length * 2
+ lastBoundaryStringLineBytes.Length
+ myFileContentDispositionBytes.Length
+ fileInfo.Length;
// And indicate the value as the HTTP request content length
requestToServer.ContentLength = totalRequestBodySize;
// Write the http request body directly to the server
using (Stream s = requestToServer.GetRequestStream())
{
// Send the file content disposition over to the server
s.Write(boundaryStringLineBytes, 0, boundaryStringLineBytes.Length);
s.Write(myFileContentDispositionBytes, 0,
myFileContentDispositionBytes.Length);
// Send the file binaries over to the server, in 1024 bytes chunk
FileStream fileStream = new FileStream(fileUrl, FileMode.Open,
FileAccess.Read);
byte[] buffer = new byte[1024];
int bytesRead = 0;
while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
{
s.Write(buffer, 0, bytesRead);
} // end while
fileStream.Close();
// Send the last part of the HTTP request body
s.Write(lastBoundaryStringLineBytes, 0, lastBoundaryStringLineBytes.Length);
string responseString = "";
WebResponse response = requestToServer.GetResponse();
using (Stream responseStream = response.GetResponseStream())
{
using (StreamReader responseReader = new System.IO.StreamReader(responseStream, Encoding.UTF8))
{
responseString = responseReader.ReadToEnd();
return responseString;
}
}
}
超时发生在using (Stream s = requestToServer.GetRequestStream())。一切都运转良好，但现在却没有。如果有人能弄清楚我的代码有什么问题，我将不胜感激。
谢谢！
修改
这里是完整的堆栈跟踪：
System.Net.WebException: Error: ConnectFailure (Connection timed out)
06-03 09:15:41.521 D/Mono ( 3839): DllImport attempting to load: '/system/lib/liblog.so'.
06-03 09:15:41.521 D/Mono ( 3839): DllImport loaded library '/system/lib/liblog.so'.
06-03 09:15:41.522 D/Mono ( 3839): DllImport searching in: '/system/lib/liblog.so' ('/system/lib/liblog.so').
06-03 09:15:41.523 D/Mono ( 3839): Searching for '__android_log_print'.
06-03 09:15:41.523 D/Mono ( 3839): Probing '__android_log_print'.
06-03 09:15:41.524 D/Mono ( 3839): Found as '__android_log_print'.
06-03 09:15:41.536 I/MonoDroid( 3839): UNHANDLED EXCEPTION:
06-03 09:15:41.537 I/MonoDroid( 3839): System.Net.WebException: Error: ConnectFailure (Connection timed out) ---> System.Net.Sockets.SocketException: Connection timed out
06-03 09:15:41.538 I/MonoDroid( 3839): at System.Net.Sockets.Socket.Connect (System.Net.EndPoint remoteEP) [0x000c2] in <filename unknown>:0
06-03 09:15:41.538 I/MonoDroid( 3839): at System.Net.WebConnection.Connect (System.Net.HttpWebRequest request) [0x0019b] in <filename unknown>:0
06-03 09:15:41.538 I/MonoDroid( 3839): --- End of inner exception stack trace ---
06-03 09:15:41.538 I/MonoDroid( 3839): at System.Net.HttpWebRequest.EndGetRequestStream (IAsyncResult asyncResult) [0x00043] in <filename unknown>:0
06-03 09:15:41.538 I/MonoDroid( 3839): at System.Net.HttpWebRequest.GetRequestStream () [0x00057] in <filename unknown>:0
06-03 09:15:41.538 I/MonoDroid( 3839): at chunkedUpload.UploadFile.upload (System.String file, System.String url) [0x000e6] in c:\Users\Ahmed\Documents\Visual Studio 2013\Projects\chunkedUpload\chunkedUpload\UploadFile.cs:115
06-03 09:15:41.538 I/MonoDroid( 3839): at chunkedUpload.MainActivity+<button_Click>d__0.MoveNext () [0x0003d] in c:\Users\Ahmed\Documents\Visual Studio 2013\Projects\chunkedUpload\chunkedUpload\MainActivity.cs:57
06-03 09:15:41.538 I/MonoDroid( 3839): --- End of stack trace from previous location where exception was thrown ---
06-03 09:15:41.538 I/MonoDroid( 3839): at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <filename unknown>:0
06-03 09:15:41.539 I/MonoDroid( 3839): at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<ThrowAsync>m__0 (System.Object state) [0x00000] in <filename unknown>:0
06-03 09:15:41.539 I/MonoDroid( 3839): at Android.App.SyncContext+<Post>c__AnonStorey0.<>m__0 () [0x00000] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Android.App/SyncContext.cs:18
06-03 09:15:41.539 I/MonoDroid( 3839): at Java.Lang.Thread+RunnableImplementor.Run () [0x0000b] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Java.Lang/Thread.cs:36
06-03 09:15:41.539 I/MonoDroid( 3839): at Java.Lang.IRunnableInvoker.n_Run (IntPtr jnienv, IntPtr native__this) [0x00009] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/platforms/android-23/src/generated/Java.Lang.IRunnable.cs:71
06-03 09:15:41.539 I/MonoDroid( 3839): at (wrapper dynamic-method) System.Object:014507e3-fd28-45b0-b68f-cb466da601fa (intptr,intptr)
An unhandled exception occured.
06-03 09:15:43.243 E/mono ( 3839):
06-03 09:15:43.243 E/mono ( 3839): Unhandled Exception:
06-03 09:15:43.243 E/mono ( 3839): System.Net.WebException: Error: ConnectFailure (Connection timed out) ---> System.Net.Sockets.SocketException: Connection timed out
06-03 09:15:43.243 E/mono ( 3839): at System.Net.Sockets.Socket.Connect (System.Net.EndPoint remoteEP) [0x000c2] in <filename unknown>:0
06-03 09:15:43.243 E/mono ( 3839): at System.Net.WebConnection.Connect (System.Net.HttpWebRequest request) [0x0019b] in <filename unknown>:0
06-03 09:15:43.243 E/mono ( 3839): --- End of inner exception stack trace ---
06-03 09:15:43.243 E/mono ( 3839): at System.Net.HttpWebRequest.EndGetRequestStream (IAsyncResult asyncResult) [0x00043] in <filename unknown>:0
06-03 09:15:43.243 E/mono ( 3839): at System.Net.HttpWebRequest.GetRequestStream () [0x00057] in <filename unknown>:0
06-03 09:15:43.243 E/mono ( 3839): at chunkedUpload.UploadFile.upload (System.String file, System.String url) [0x000e6] in c:\Users\Ahmed\Documents\Visual Studio 2013\Projects\chunkedUpload\chunkedUpload\UploadFile.cs:115
06-03 09:15:43.243 E/mono ( 3839): at chunkedUpload.MainActivity+<button_Click>d__0.MoveNext () [0x0003d] in c:\Users\Ahmed\Documents\Visual Studio 2013\Projects\chunkedUpload\chunkedUpload\MainActivity.cs:57
06-03 09:15:43.243 E/mono ( 3839): --- End of stack trace from previous location where exception was thrown ---
06-03 09:15:43.243 E/mono ( 3839): at (wrapper dynamic-method) System.Object:014507e3-fd28-45b0-b68f-cb466da601fa (intptr,intptr)
06-03 09:15:43.243 E/mono ( 3839): at (wrapper native-to-managed) System.Object:014507e3-fd28-45b0-b68f-cb466da601fa (intptr,intptr)
06-03 09:15:43.244 E/mono-rt ( 3839): [ERROR] FATAL UNHANDLED EXCEPTION: System.Net.WebException: Error: ConnectFailure (Connection timed out) ---> System.Net.Sockets.SocketException: Connection timed out
06-03 09:15:43.244 E/mono-rt ( 3839): at System.Net.Sockets.Socket.Connect (System.Net.EndPoint remoteEP) [0x000c2] in <filename unknown>:0
06-03 09:15:43.244 E/mono-rt ( 3839): at System.Net.WebConnection.Connect (System.Net.HttpWebRequest request) [0x0019b] in <filename unknown>:0
06-03 09:15:43.244 E/mono-rt ( 3839): --- End of inner exception stack trace ---
06-03 09:15:43.244 E/mono-rt ( 3839): at System.Net.HttpWebRequest.EndGetRequestStream (IAsyncResult asyncResult) [0x00043] in <filename unknown>:0
06-03 09:15:43.244 E/mono-rt ( 3839): at System.Net.HttpWebRequest.GetRequestStream () [0x00057] in <filename unknown>:0
06-03 09:15:43.244 E/mono-rt ( 3839): at chunkedUpload.UploadFile.upload (System.String file, System.String url) [0x000e6] in c:\Users\Ahmed\Documents\Visual Studio 2013\Projects\chunkedUpload\chunkedUpload\UploadFile.cs:115
06-03 09:15:43.244 E/mono-rt ( 3839): at chunkedUpload.MainActivity+<button_Click>d__0.MoveNext () [0x0003d] in c:\Users\Ahmed\Documents\Visual Studio 2013\Projects\chunkedUpload\chunkedUpload\MainActivity.cs:57
06-03 09:15:43.244 E/mono-rt ( 3839): --- End of stack trace from previous location where exception was thrown ---
06-03 09:15:43.244 E/mono-rt ( 3839): at (wrapper dynamic-method) System.Object:014507e3-fd28-45b0-b68f-cb466da601fa (intptr,intptr)
06-03 09:15:43.244 E/mono-rt ( 3839): at (wrapper native-to-managed) System.Object:014507e3-fd28-45b0-b68f-cb466da601fa (intptr,intptr)